Electrically heated footwear



Dec. 20, 1966 J. COSTANZO 3,293,495

ELECTRICALLY HEATED FOOTWEAR Filed Sept. 13, 1965 INVENTOR Rapfiael J 60522020 KL BY United States Patent 3,293,405 ELECTRICALLY HEATED FOOTWEAR Raphael J. Costanzo, 119 Park St., Bridgeport, Conn. 06608 Filed Sept. 13, 1965, Ser. No. 487,011

4 Claims. (Cl. 219-211) This invention relates in general to an electrically heated footwear, .and more specifically to an electrically heated sock having a circuit including an electric power source and electric heater operatively connected thereto wholly contained within the sock.

Considerable efiorts have been made to attain a highly efiicient electrically heated footwear as for example, a sock to keep ones feet warm. Heretofore all the known efi'orts to electrically heat such a sock required a source of electrical power which was extraneous or remotely disposed from the sock itself, e.g., a fixed source, such as household or vehicle power, or a portable power pack carried on the persons body. When the line current from a fixed source of electrical power was utilized, mg. in a home or vehicle, the mobility of the person wearing such heated sock or footwear w as necessarily limited to the length of cord or wire required for conducting the cur-rent from the fixed power source to the sock. Consequently, such socks had only limited application, as for example when sleeping, resting or when flying an airplane or ope-rating some other vehicle wherein movement of the wearer was necessarily confined and Where sufficient power was available to energize the heater of such socks.

To obviate the mobility handicap of such electrically heated footwear socks, efforts have been made to provide a portable power pack by which the heater of such socks or footwear may be energized. Because of the energy heretofore required to energize the heater used in such socks, such efforts resulted in utilizing a relatively large sized battery or power pack which had to be worn by the wearer about his waist. For this reason long conductors or wires were required to extend along the body of the wearer to connect the power pack to the heating means disposed within the sock or footwear. Such power pack-s, however, due to the size requirements of the battery necessary to energize such heaters, were relatively 'bulky, heavy and cumbersome to wear. Also, the wires required to extend from the power pack and the sock Igreatly interferred with the mobility of the person wearing such sock and associated power pack unit.

It'is, therefore, an object of this invention to provide a heated footwear, sock or the like with an improved type electrical heating means capable of operating on very low voltages, whereby the power source to energize the same comprises a small, low voltage hattery which can 'be concealed wholly within the footwear or sock itself.

Another object of this invention is to provide an improved heated' sock which is completely immersible in Water and consequently'can be either machine or handwashed with ease and without adversely affecting the- Ice Another object of this invention is to provide an electrically heated sock having an entirely self-contained source of electrical energy and heater energized thereby.

Another object of this invention is to provide in an electrically heated wear a circuit including a low voltage, battery and connected heater with provisions for conserving the useful like of the battery to its maximum extent.

The foregoing objects and other features and advantages are attained by an electrically energized footwear as for example, a sock which may be of conventional construction, i.e. it may be either woven or knitted, and comprising essentially of a toe portion, a heel ortion and a connected leg portion with the usual elastic top or band adjacent the upper end thereof. In accordance with this invention an electrical heating means is located Within the sock. The heating means is preferably located adjacent to toe portion of the sock and it is energized entirely :by a low voltage battery which is also carried within the sock itself. Accordingly, a means is located adjacent to the upper end or band of the sock to define a pocket for containing a holder to which a small low voltage battery is detachably secured. In the toe portion of the footwear there is formed a pocket for receiving the heating means. In accordance with this invention the heating means comprises an electrical resistor form of a flat strip of high electrical resistant material, as for example Nichrome. The resistor is operatively connected in circuit to the battery by means of conductors which run along the inside of the sock. To enhance the heating characteristic of .the heating means, a radiating surface is operatively connected to the elec trical resistor in heat transfer relationship. The radiation surface comprises fiat metallic sheet material or foil which is electrically insulated but in an heat conducting relationship with the electrical resistor. Accordingly, the arrangement is such that the heating means can he shaped to conform to any desired shape. By utilizing a flat element added comfort is attained to the wearer of such footwear.

' To conserve the useful life of the battery, a circuit breaking means is interposed in the circuit between the heating means and the battery, which in effect operates as .a thermostat, intermittently breaking and making the circuit, as determined by the power requirements thereof.

A feature of this invention resides in an electrically heated footwear or sock having a self-contained electrical power source and heating means operatively connected thereto.

Another feature of this invention resides in electrically heated sock which is readily Washable.

Another feature of this invention resides in the provision of utilizing the heater construction which includes an electrical resistor with connected heat radiating surfiaces so as to expand the heating area of the heater.

Another feature of this invention resides in the provision of an improved heating element which can be energized by a very low voltage battery.

Another feature of this invention resides in the provision of an improved electrically heated sock or the like which can be worn with all the comfort and convenience of ordinary sock or footwear.

Other features and advantages will become more readily apparent when considered in view of the description and drawings in which:

FIGURE 1 illustrates a sectional side view of a sock construction embodying the instant invention.

FIGURE 2 illustrates a prospective view of the improved electrical heater and source of power necessary to energize the same, as utilized in the sock construction of FIGURE 1.

FIGURE 3 is a schematic illustration of the electrical circuit utilized in the sock constructionof FIGURE 1.

FIGURE 4 is a sectional view of the heating means taken along line 4-4 on FIGURE 2.

Referring to the drawings there is shown therein an improved footwear construction embodying the instant invention, which is herein illustrated as a sock. The sock 10 may be conventionally formed, i.e. woven or knitted, and comprises generally of a toe portion 10A, a heel portion 141B, and a connected leg portion 10C having an elastic band 11 or the like adjacent the upper end thereof.

In accordance with this invention the sock 10 is electrically heated by means of a low voltage heating means 12 suitably positioned within the sock 10. In the illustrated form of the invention, the heating means 12 is located adjacent the toe portion 10A of the sock. To accommodate the heating means 12 Within the sock there is formed an internal pocket 13 in the toe portion 10A.

The heating means 12 as best seen in FIGURE 2 is readily inserted into the pocket 13 which is defined by the sole or bottom portion of the sock and a layer of material 13A which is sewn adjacent thereto on the inside surface of the sock. The heating means 12 comprises a flat strip of electrical resistance material 14, as for example Nichrome. The Nichrome strip or resistor 14 in turn is connected in circuit with a suitable source of electrical power as for example, a low voltage battery 15 which is adapted to be carried in the sock 10 itself.

In the illustrated form of the invention the battery 15 is carried in the pocket 16 formed in the upper end of the sock; and preferably in the band portion 11 thereof. The size of the pocket 16 is such that it can readily accommodate the battery holder 17 and a small low voltage battery 15 for energizing the heater 12 as will behereinafter described. The holder 17 is constructed so that the battery can releasably attach thereto.

As best seen in FIGURE 2, the battery holder 17 comprises a base member 18 which has connected thereto a pair of spring finger or terminals 19, 20 which are arranged to engage with the terminal portions of the battery 15. Connected to or integrally formed with the front finger or terminal 19, is a resilient clip 21 which serves to embrace the side portions of the battery 15 as shown. Accordingly, the battery 15 can be readily releasably attached to the holder 17 by positioning the same between the terminal fingers 19, 20 and associated clip 21. Accordingly the battery is frictional-1y retained against longitudinal movement by means of the spring finger terminals 19, 20, and against lateral movement by the spring clip portion 21.

Suitable conductors 22, 23 connect the battery into circuit with the heater 12. Accordingly the ends of one conductor 23 are connected between the Nichrome strip 14 and the battery terminal 20. The other conduit or Wire 23 is connected to the other battery terminal 19 and the other end of the Nichrome strip 14. With the resistors so connected, it is placed in circuit with the battery when the battery is placed in the holder 17. A suitable binding'24 conceals or covers the conductors 22, 23 against the leg portion of the sock.

' The heating surface of the Nichrome strip 14 is enhanced by radiation means connected in heat transfer relationship therewith. In the illustrated form of the invention, the heat radiating means comprises a sheet of heat conducting material, as for example, metallic foil 25, such as aluminum foil or the like which is connected in heat transfer relationship to the Nichrome strip 14. In the illustrated embodiment, two similar strips 25, 25A may be disposed in back to back relationship on either side of the resistant element so as to be secured theerto in heat transfer relationship with it and each other. A suitable means for securing the foil to the resistor 14 may be by applying an adhesive coating 25 to the back of the foil. Accordingly the adhesive coating 25 also functions to electrically insulate the electrical resistor from the foil while at the same time securing the foil 25, 25A in heat transfer relationship to the resistor 14. The foil 25, 25A may be also electrically insulated by anodizing the foil.

As shown, the heating area or surface of the resistor 14 can be expanded to any desired width or shape depending upon the shape and form of the radiating strips 25, 25A. Thus, with a very narrow resistor, the heat therefrom can be effectively distributed over a relatively large area. Consequently the heat generated is not confined to a single point, but is comfortably distributed for uniform heating.

In the illustrated form of the invention it will be readily noted that the heating means 12 wasiinitially formed as an elongated member which was subsequently folded to define the U-shape heater 12 which is readily inserted into the toe pocket 13 of the sock 10.

In operation, it will be noted that whenever the battery 15 is interposed between the terminals 19, 20 of the battery holder, the circuit to the heater will become energized.

If desired, a suitable switching means (not shown) may be connected in series between the battery 15 and the heating element 12 so as to control the operation of the circuit.

In accordance with this invention a means is provided for extending the life of the battery. Experience has shown that the temperature required to be generated by the heater need be only slightly greater than that of normal body temperature to keep ones feet warm. For this reason the power requirement to energize the heater need not be constant. For this reason the heater circuit can be intermittently operated, as may be required by the body temperature or demand of the wearer. This is attained by interposing an automatically operating circuit breaker 26 of known construction in the line between the battery 15 and the heater. Accordingly the circuit breaker is constructed so that it will function as a thermostat for intermittently making and breaking the circuit to the heater according to the power requirements. Accordingly by utilizing intermittent operation, it has been discovered that the useful life of the battery 15 can be substantially extended.

The heating means 12 described is arranged and constructed to operate with very low voltage battery. Forexample, three to four 1 /2 volt batteries may be utilized to energize the heater, or a 3 volt battery can satisfactorily energize the heater 12. Also 2 D cell batteries can be used to energize the heater 12.

From the foregoing it will be readily noted that the heated footwear 10 described comprises a wholly contained unit in which the source of power 15 and the heater 12 can be wholly disposed within themakeup of the sock 10 itself. The entire sock 10 is relatively light in weight and which when worn can be worn with the convenience and luxury of an ordinary sock. Consequently, the wearer is not required to wear any bulky power pack unit which is rendered readily apparent to another person. With the invention described, the footwear is given all the appearance and has all the comfort of a conventional footwear, but with the added provision that a source of heat is provided to add additional comfort in extreme cold. Accordingly, the heated sock has particular application as sport wear, e.g. hunting and/or fishing in the cold, or cold climates, and can be worn so as to not interfere in any manner with the movements of the wearer. Also, the overall weight thereof is reduced to a minimum.

While the instant invention has been particularly defined as applied to an electrically heated sock it will be readily noted that the novel heating means may be readily applicable to other body heating garments and/or applications. Therefore, while the instant invention is disclosed and described with reference to a heated sock, it will be readily understood and appreciated that variations and modifications'may be made without departing from the spirit or scope of the invention.

What is claimed is:

1. In combination:

(a) a woven sock having a toe portion, a heel portion and a connected leg portion,

(b) means defining a pocket adjacent the upper end of said leg portion,

(0) a holder adapted to releasably secure a low voltage battery in said pocket,

(d) electrical non-conductive means defining a pocket in the toe portion of said sock,

(e) a heater disposed in said toe pocket,

(f) said heater including a flat resistor strip of electrical resistance material,

(g) radiation means connected in heat transfer relationship to said flat resistor strip for defining an expanded radiation surface for said heater,

(h) said radiation means including a pair of heat conducting sheets of material for sandwiching said resistor strip in heat transfer relationship therebetween,

(i) means joining said heat conducting strips together and electrically insulating said strips from said resistor strip,

(j) electrical conductors connecting said resistor strip in circuit to said battery,

(k) means for maintaining said conductors against the leg portion of said sock,

(l) and a circuit breaker connected in circuit with said heater to intermittently make and break the circuit.

2. In combination (a) a woven sock having a toe portion, a heel portion and a connected leg portion,

(b) means defining a pocket adjacent the upper end of said leg portion adapted to receive a low voltage battery of less than 6 volts,

(c) electrical non-conductive means defining a pocket in the toe portion of said sock,

(d) a heater disposed in said toe pocket,

(e) said heater including a flat resistor strip of electrical resistance material,

(f) radiation means connected in heat transfer relationship to said flat resistor strip for defining an eX- panded radiation surface for said heater,

heat conducting sheets of material comprise metallic foil connected in heat transfer relationship to said resistor strip.

4. The invention as defined in claim 2 wherein said means joining said heat conducting strips comprise an adhesive coating on one side of said heat conducting strips whereby said heat conducting strips of material are adhesively secured in back to back relationship to sandwich said resistor strip therebetween in heat transfer relationship therewith.

References Cited by the Examiner UNITED STATES PATENTS 1,312,830 8/1919 Camm 219528 X 1,558,278 10/1925 Phillips 219-472 X 1,702,583 2/1929 Williams 219211 2,277,772 3/1942 Marick 219-211 2,329,766 9/ 1943 Jacobsen 219211 2,692,326 10/1954 Crowell 219211 3,010,007 11/1961 Theodore et a1 219345 3,079,486 2/1963 Winchell 219-528 3,084,241 4/1963 Carrona 219-211 FOREIGN PATENTS 116,344 12/1942 Australia. 546,812 7/ 1942 Great Britain.

RICHARD M. WOOD, Primary Examiner.

V. Y. MAYEWSKY, Assistant Examiner.

Disclaimer ,293,405.Ra;0hael J. OOnstanzo, Bridgeport, Conn. ELECTRICALLY HEATED FOOTWEAR. Patent dated Dec. 20, 1966. Disclaimer filed Jan. 17, 1977, by the inventor. Hereby enters this disclaimer to claims 1 through 4 of said patent.

[Ofiioz'al Gazette March 2%, 1.977.] 

2. IN COMBINATION (A) A WOVEN SOCK HAVING A TOE PORTION, A HEEL PORTION AND A CONNECTED LEG PORTION, (B) MEANS DEFINING A POCKET ADJACENT THE UPPER END OF SAID LEG PORTION ADAPTED TO RECEIVE A LOW VOLTAGE BATTERY OF LESS THAN 6 VOLTS, (C) ELECTRICAL NON-CONDUCTIVE MEANS DEFINING A POCKET IN THE TOE PORTION OF SAID SOCK, (D) A HEATER DISPOSED IN SAID TOE POCKET, (E) SAID HEATER INCLUDING A FLAT RESISTOR STRIP OF ELECTRICCAL RESISTANCE MATERIAL, (F) RADIATION MEANS CONNECTED IN HEAT TRANSFER RELATIONSHIP TO SAID FLAT RESISTOR STRIP FOR DEFINING AN EXPANDED RADIATION SURFACE FOR SAID HEATER, 